Forensics Ch 2 Test
1. distance scale 2. date and location of the crime scene 3. a north heading - important in marking & measuring evidence positions
crime scene sketches must have:
subdatum point
established from datum point using a stake; located between datum points
Direct evidence
first-hand observations
paper bindle
ideal packaging for small, dry, trace evidence
Class evidence
narrows an identity to a group of persons or things
individual evidence
narrows an identity to a single person or thing
forensic lab technicians
specialized to process only one type of evidence - they ANALYZE the evidence
11. This evidence found is not sufficient enough to convict the suspect because it is circumstantial evidence. The hair follicle and fingerprint found could be leftover particles that prove that someone was at the crime scene, but does not directly link them to committing the crime itself. The hair follicle can be used as class evidence to narrow down the suspect list. Although the fingerprint and follicle are individual evidence, the possible suspect could have been a friend of the victim and wrongly accused for this crime. There was no direct evidence found at the scene that links this specific suspect to the crime, therefore the hair follicle and fingerprint found is not sufficient enough.
(11.) A suspect is linked to a murder by the presence of hair found on a chair at the victims' house and a fingerprint found on the coffee table. Crime-scene inves-tigators found a fingerprint consistent with a suspect's fingerprint, and they found the hair to be similar to the hair from the head of the same suspect. Provide arguments that this evidence is not sufficient to prove the suspect was the murderer. Include the following terms in your answer: Obj. 2.1, 2.2, 2.3 • Circumstantial evidence • Class evidence • Individual evidence • Direct evidence
Prevent witnesses from talking to each other
(2) The reason it is important to separate witnesses at the crime scene is to
All of the above - documenting the location where the evidence was found - correct packaging of evidence - maintaining proper chain of custody
(3) Correct collection of evidence requires which of the following:
the type of search pattern used to collect the evidence
(4) A crime-scene sketch should inclue all of the following except:
Case 1: The sketch artist forgot to sketch the two windows, the closet, and the door. This information about the room itself is the datum point, which will help map out the rest of the crime scene for the investigators to follow.
(8) Identify the errors in each of the following cases: Case 1 A dead body and a gun were found in a small room. The room was empty except for a small desk and a chair. The room had two windows, a closet, and a door leading into a hallway. The crime-scene sketch artist measured the perim-eter of the room and drew the walls to scale. He sketched the approximate position of the dead body and the gun. He sketched the approximate location of the chair and the desk. What did he forget to do?
Locard's Principle of Exchange
- when a person comes in contact with an object or another person, a cross-transfer of physical material can occur - the intensity, duration, and nature of the entities & contact determine the extent of the transfer
grid, linear, quadrant/zone, spiral
4 crime scene search patterns:
Leftover particles (DNA, hair follicles, fibers, fingerprints) that prove you were somewhere, but cannot prove you did it.
Examples of circumstantial evidence
All 1 blood type, all same hair color, etc.
Examples of class evidence
physical & biological physical ex: physical items biological ex: DNA, blood, bodily fluids FINGERPRINTS can be either!!!!
Types of circumstantial evidence
a) get original evidence bag b) open evidence bag maintaining signature on the 1st seal c) the original evidence bag with the uncut seal & 1st signature should have an UPDATED chain of custody log in a NEW sealed & signed evidence bag
Chain of custody procedure:
Arson Murder staged to look like a suicide Burglary
Commonly staged types of crime scenes include:
a) determine placement of evidence b) place the dried evidence on bindle paper c) secure bindle in labeled evidence bag using stick-on label d) write the collector's signature across the bag's taped edge
How to package dry evidence:
circumstantial evidence
Indirect evidence that can be used to imply a fact but that does not prove it.
- could do it for insurance fraud money $ - efforts to try and cover a murder > medical examiners can tell by smoke in the lungs if someone was killed before/during the fire -----> no smoke in lungs- killed b4 fire -----> smoke in lungs- killed in the fire
Why would someone stage a crime scene to look like ARSON?
to cover up a murder - medical examiner can tell if it was a suicide or staged suicide because markings will look different if they are staged/real
Why would someone stage a crime scene to look like SUICIDE?
insurance fraud money $$$$$$$$$
Why would someone stage a crime scene to look like a BURGLARY?
datum point
a permanent, fixed point of reference used in mapping a crime scene
- forming a hypothesis of the sequence of events from before the crime was committed through its commission - comparing the evidence to witneses statements > investigators must keep an open mind as they examine all possibilities
what does crime scene reconstruction involve?
Crime scene directions of north, south, east & west
what must be included when marking evidence, collectiving limits, and measuring & marking evidence positions?
police officers crime-scene investigators medical examiners detectives specialists
who makes up a crime-scene investigation team?
Blood spatter can be used to identify blood type
(1) Locard's Principle of Exchange implies all of the following except:
Knowing the blood type as class evidence can be useful because it narrows down the victim or suspect list to people with only that particular blood type.
(5) Blood type is considered to be class evidence. Although it may not specifi-cally identify the suspect, explain how it still could be useful in helping to investigate a crime.
b) The photographer would have to take pictures and record all aspects of the crime scene, including all types of evidence, locations, bodies, and weapons. The recorder will obtain these pictures and videos.
(6) The recorder at the crime scene needs to work with all of the police per-sonnel at the crime scene. What type of information would the recorder need to obtain from each of the following persons? (b) photographer
c) The sketch artist will draw a sketch of the suspect using information given by any eyewitnesses. The sketch artist will also sketch the crime scene and all of its features, and will include north/south directions and measurements. The recorder will need to obtain all sketches that were made of the crime scene and any suspects.
(6) The recorder at the crime scene needs to work with all of the police per-sonnel at the crime scene. What type of information would the recorder need to obtain from each of the following persons? (c) sketch artist
- evidence that is wet or contains bodily fluids must be air dried completely!!!! - once in a secure location & completely air dried, that evidence can be repackaged in a new, dry paper container
How to package wet/bodily fluids evidence:
1) Securing the Scene 2) Separating the Witnesses 3) Scanning the Scene 4) Seeing the Scene 5) Sketching the Scene 6) Searching for Evidence 7) Securing and Collecting Evidence
What are the 7 S's of Crime Scene Investigation?
intensity, duration, and nature of the entities & contact
What determines the extent of material transfer? (locard's)
Must know and document who/when someone had the evidence to maintain the integrity of the evidence - must maintain chain of custody in order for evidence to be legally used in court
What is the purpose of keeping a chain of custody?
MUST keep an OPEN mind when examining all possibilities! > cannot directly make assumptions
What must investigators do during crime scene reconstruction?
d) The evidence collection team is responsible for observing the evidence first, making sure it is photographed and documented, and then they can collect it. The evidence collection team must properly package and handle each piece of evidence to maintain a chain of custody. The recorder will need to obtain information on who collected the evidence, who has the evidence currently, and how it was handled.
(6) The recorder at the crime scene needs to work with all of the police per-sonnel at the crime scene. What type of information would the recorder need to obtain from each of the following persons? (d) evidence collection team
From the first responding officer, the recorder would need to obtain information about what was going when the first responder arrived, how the first responder secured the scene, make sure that the evidence was not contaminated, and will maintain a log of who entered the crime scene. The recorder will also need to obtain information on the materials requested by the first responder from the crime scene, who has visited, what civilians are involved, and know about any apparent evidence.
(6) The recorder at the crime scene needs to work with all of the police per-sonnel at the crime scene. What type of information would the recorder need to obtain from each of the following persons? Obj. 2.4, 2.7 a) first-responding officer
b) By taking nail clippings from the deceased, you can obtain any possible DNA left underneath the nails that could belong to the suspect. The investigators can also see if any debris or particles were left under the nails that could be used as circumstantial evidence or that would help identify the suspect. - if the victim scratched the perpetrator, there will be evidence & DNA underneath the nails
(7) When the crime-scene investigators arrive at a potential homicide scene, one of their duties is to collect evidence from the victim's body. However, some evidence needs to be collected from the body at a later time in the morgue. For each type of situation listed, describe the type(s) of evidence that could be obtained by: Obj. 2.6, 2.7, 2.8, 2.9 (b) taking nail clippings from the deceased
c) Placing a plastic bag over the hands of the deceased before transporting the body to the morgue will allow investigators to look for any trace or direct evidence. The investigators can also fingerprint the victim to see if it matches any fingerprints from the crime scene, and check for any particles, blood samples, or fibers left on the hands of the deceased. - any residue left on the hands will be covered and prevented from getting contaminated
(7) When the crime-scene investigators arrive at a potential homicide scene, one of their duties is to collect evidence from the victim's body. However, some evidence needs to be collected from the body at a later time in the morgue. For each type of situation listed, describe the type(s) of evidence that could be obtained by: Obj. 2.6, 2.7, 2.8, 2.9 (c) placing a plastic bag over the hands of the deceased before transport-ing the person's body to the morgue
d) Brushing the clothing of the victim with a clothes brush allows the investigator to look for any types of trace evidence left on the victim's body. The investigators could find hair follicles, animal furs, fibers, or particles from the suspect left on the victim's clothing. - leftover hair follicles, animal fur
(7) When the crime-scene investigators arrive at a potential homicide scene, one of their duties is to collect evidence from the victim's body. However, some evidence needs to be collected from the body at a later time in the morgue. For each type of situation listed, describe the type(s) of evidence that could be obtained by: Obj. 2.6, 2.7, 2.8, 2.9 (d) brushing the clothing of the victim with a clothes brush
a) By transporting the body in a closed body bag, the types of evidence obtained from this would be any fibers, particles, or fingerprints left on the body. You can also find out about any fluids that were left on the body that belonged to the victim or suspect. All of this will help narrow down possible suspects and identify the victim. - keeps outside things from getting on the body & contaminating it - keeps all potential evidence inside the bag
(7) When the crime-scene investigators arrive at a potential homicide scene, one of their duties is to collect evidence from the victim's body. However, some evidence needs to be collected from the body at a later time in the morgue. For each type of situation listed, describe the type(s) of evidence that could be obtained by: Obj. 2.6, 2.7, 2.8, 2.9 a) transporting the body in a closed body bag
Case 2: The evidence collector should not have wrapped the bloody, damp shirt in a paper bindle because the paper bindle is to hold dry trace evidence, not wet evidence. The shirt needs to be kept in a somewhat open container to prevent mold from growing.
(8) Identify the errors in each of the following cases: Case 2 At the scene of the crime, the evidence collector found a damp, bloody shirt. The evidence collector quickly wrapped the shirt in a paper bindle. He inserted the paper bindle with the shirt into an evidence bag. The bag was sealed with tape, and the collector wrote his name across the tape. The CSI also picked up three cigarette butts and put them into a plastic evidence bag, which he sealed and labeled. An evidence collection log was completed and taped to each of the evidence bags. What did he do incorrectly?
Case 3: The lab technician should not have removed the crime-scene evidence collector's signature because the evidence now only shows the lab technician's name, and not who collected the evidence. The lab technician also opened and sealed the evidence bag in the same spot as the evidence collector did, but she should have reopened it in a different spot than and placed it in a new evidence bag.
(8) Identify the errors in each of the following cases: Case 3 Several different labs often need to share a small amount of evidence. It is impor-tant that the chain of custody be maintained. If the chain of custody is broken, then the evidence may not be allowed in a court proceeding. Identify the break in the following chain of custody. After obtaining evidence, a lab technician removed the tape that contained the signature of the crime-scene evidence collector. Upon completion of her examination of the evidence, the lab technician put the evidence back into a paper bindle, and inserted the bindle into an evidence bag. The technician resealed the bag in the same place as the original crime-scene investigator. After carefully sealing the bag, the lab technician signed her name across the tape. She completed the chain-of-custody form on the outside of the evidence bag and brought the evidence to the next lab technician at the crime lab.
confessions, eyewitness accounts, camera footage
Examples of direct evidence:
Fingerprint, DNA
Examples of individual evidence